Hi, Rose,
I think a lot of students have probably bought a box
of "flash cards" for learning new words.
The problem is: most people are not disciplined enough
to progress beyond words starting with the letter A!
But it still takes some effort. So if you cannot
make a commitment to work hard at it, you can stop
reading this now.

I would suggest that unless you
are very disciplined, you should build your vocabulary
through the following:

1. reading - reading is
essential for building a well-rounded vocabulary at
a level that is suitable for you. You can read
newspapers, novels, and even magazines.
(Readers' Digest is a good one to read since
the stories and articles are not long.)

2. writing - what you don't use, you lose!
So it is important that you make use of the words and
phrases you learn. Write letters, write a diary,
write stories...

3. note-taking - use a notebook
to write down words and phrases that you have read
and would like to learn. Look them up in a
dictionary and write down the meanings. Be sure to
write down examples of how they are used. Then from
time to time review them.